Regulator



C. H. SMOOT May 31, T932.'

REGULATOR Filed April 16, 1929 lNvENToR @km/.wwwa M MJ.

%f ATTORNEYS.

Patented May 3l 1932 CHARLES H. SHOOT, F EAPLEWOOD, NEW

REGULATOR Application med April 16, 1929.. Serial lo. 355,488.

My invention relates cto the art of regulation and comprises a sensitivera'pid acting anti-hunting regulator of the type wherein a force varyingas a function of the element controlled opposes a regulating force toeffect the regulation through auxiliary power means.

My present invention is in some res ects like and in some respectsunlike that o the 1o re ulator of my PatentNo. 1,658,577 dated Fe ruary7 1928, and comprises an improvement thereover whereby more rapid andaccurate regulation lmay be obtained. As in the patented device,'myregulator comprises a balance acted upon by a orce va ing as afunction'of the element controll and by controlling forces which upondeparture from neutrality throw into operation means for controllin theelement and means for temporarily a ding a force to the balance in adirection to restore equilibrium thereupon. In the patented device theaddition of the temporary forceto the balance, and the control of theelement, were effected by two electric motors connected in parallel andconsequently operated simultaneously, and the removal of the temporaryforce was e'ected by a third electric motor. In my present regulator, Ihave provided means whereby 3o two motors, one e ecting both theaddition and removal of the temporary force and the other effecting thecontrol of the element are connected in parallel during onl a part ofthe time; the re ulating motor ing operated at times in ependently ofthe other to effect a micrometer adjustment and insure a completerestoration of the balance upon removal of the temporary force. Theoperation of my present regulator is such as to 4.0 cause an initialover-travel of the regulated element followed by an automatic return toits final position.

For a better understandin of my invention reference should be hafta theaccompanying drawing in which one modification of my invention isillustrated 'as applied to the regulation of pressure.

Referring to the drawing, a damper 1 e1'- fects the control of the flowof Huid throu h '50* a conduit 2. In the specic modification 1llustratedthe damper is operated to maintain constant the iiuid pressure at someoint in the ow and is adjusted to the positlon corresponding to thedesired pressure by a reversible electric motor 3 hereinafter called 55the re ulating motor, which turns the damper in eit er direction bymeans of arack 4 and worm gear 5 mounted on'the shaft 6 of the motor.The regulating motor is brought into operation by means hereinafterdescribed upon departure from the balanced condition o a pivoted lever 7The regulating force acting upon the balance lever 7 is in this instancea constant and comprises the weight 8. The force var ing 05 as afunction of the element controlled 1s in this instance the pressure ofthe fluid iowing in conduit 2 whlch varies with the damper position, andthis force is transmitted to the balance 7 by means of a pipe 9connected to 70 conduit 2 and terminating within an inverted pressurebell 10 partially submerged in liquid and carried by the lever 7.

Means for temporarily adding a force to the balance comprise avertically movable rod 11 carrying between two projections 12 and 13thereupon a tension spring 14, the mid oint of which is attached to theend of lever g., The rod 11 normally holds the spring 14 in suchposition as to exert no turning moment on the lever. The rod is movableverticall but is prevented from rotating by means o? a fixed key 15which rests in a longitudinal slot 16 in the rod. The lower portion ofrod 11 is threaded and has mounted 85 thereupon a ear 17 rotatablymounted in a stationary co ar 18, which gear meshes with a gear 19mounted on the shaft of a reversible electric motor 20, hereinaftertermed the compensating motor. Operation of the compensatin motor thusraises or lowers the rod 11 and t ereby causes spring 14 to apply eitheran upward or downward force to the right-hand end of the balancedepending upon the directions of rotation of the motor. @ne terminal ofthe com ensating motor 20 is connected through lead wire 21 with oneside of a source of power, indicated dia-grammatically by the terminals22, and the other terminals of the motor are connected to sta- 109 withthe other side of the source of power 22.V

The arrangement is such that a closure of contacts 23 and 25 due to adecrease in the Huid pressure within bell 10, causes the compensating.motor to operate in such direction as to lower rod 11, thus adding adownward force to lever 7 by the increase in tension inthe lower half ofspring 14, which force is in a direction to return the balance toneutral. Conversely, closure of contacts 24 and 25 causes thecompensating motor to raise rod 11 to apply, through spring 14, anupward force to the end of lever 7, or to remove the additional downwardforce if rod 11 had been displaced downward from normal position.

A frame 27, carrying electrical contacts 28v and 29, is mounted inbearings-30 to the right ofthe upper part of rod lland is adapted to Ybe'intermittently moved horizontally against the tension of springs 31by a cam 32 bearing against a projection 33 on the frame. Cam 32 iscontinuously rotated by a motor 34 and is so shaped as to move frame 27to the left for a relatively short period of time during cach completerotation of the cam. Rod 11 carries a contact 35 which is adapted toengage one or the other of contacts 28 and 29 when frame 27 is moved tothe left and when rod 11 is in other than normal position. When frame 27is returned to the right by springs 31 contact 28 enga es a stationarycontact 36 which is electrically connected through conductor 37 withcontact 24, and contact 29 engages a stationary contact 38 electricallyconnected through conductor 39 with contact 23. Contacts 28 and 29 areconnected to two of the terminals of the regulating motor 3 by leadwires 40 and 41 respectively, the other terminal of the motor beingconnected to the source of power.

The electrical connections are such that when frame 27 is held to theright, and contacts 28 and 29 engage contacts 36 and 38 respectively,the regulating motor is connected in arallel with the compensatingmotor, and 1f balance 7 has departed from neutral will operate toturn'the damper in such direction as to restore neutrality. When cam 32moves frame 27 to the left, no operation of the regulating motor occursunless rod 11 is displacedfrom normal as neither contact 28 nor 29 willengage contact 35 unless contact 35 is displaced in one direction oranother. If, however, rod 11 rhas been raised, due to closure ofcontacts 24 and 25 resulting from an increase in pressure within bell10, or from a decrease in the controlling force, such i Aas a shift ofweight 8 to the right, contact 35' will engage contact 28 when -frame 27is moved to the left, thus closingone circuit for the regulating motorand causing it to close with, and at other times acts independentyx.

of and in the Asame or opposite direction wi the compensating motor,

The operation of the entire regulator lis as lfollows: Assuming theapparatus to be initially in a condition of equilibrium with thepressure within bell 10 equal to that for which weight 8 is adjusted,motors 3 and 20 will be idle, balance 7 will be in neutral position withcontact 25 out of en gement with either "contact 23 or 24, and rame 27will be reciprocated horizontally without closin the circuit of theregulating motor inv eit ier extreme position of movement. If now, forany reason, a change occurs in the flow through conduit 2, the balanceof forces upon lever 7 will be upset by a change in pressure withinbell' 10. Assuming a change in flow in such direction as to cause anincrease in pressure, lever 7 will be moved to close contacts 24 and 25and to thus throw the compensating motor into operation in such adirection as to lift rod 11. The regulating motor will likewise bethrown into operation by the closure of contacts 24 and 25 for so muchof each period of rotation of cam 32 as permits sprin s 31 to hold frame27 to the right, and the irection of rotation of the regulating motorduring these periods will be suchvas to tend to close damper 1.A Duringthe relatively short periods at which cam 32 forces frame 27 to theleft, the regulating motor will be operated in the same direction, viz:to close the damper, as rod 11 is in a raised position due to operationof the compensating motor, contact 35 engaging contact 28. After aperiod of operation of the device as above described, the increased tralposition, thus separating contacts 24 and 25 and breaking the circuit ofthe compensating motor. The circuit of the regulating motor willlikewise be opened during the period of engagement of contacts 28 and 29with contacts 85 and 86 respectively. The pressure reduction due toclosure of the damper'gradually is felt upon the balance and lever 7then tips to close contacts 23 and 25. throwing the compensating motoragain into operation, this time to lower rod 11 to return it to itsnormal position. The regu- 1 lating motor will then operate during the Ytime that frame 27 is to the right, in a direction to open damper 1,while operating in the reverse direction while frame 27 is to the left.YWhen rod 11 is returned to normal, the temgraryl force has beencompletely removed m t e balance and the opera- 4 opposite movement ofthe eration of the specific apparatus described upon departure romnormal balance of the regulated and regulating forc involves thefollowing steps: (1) a continual addition of a-.force to the balance anda relatively rapid movement of the damper both in the direction tendingto equilibrium of the balance; (2) three-force artificial equilibrium ofthe balance and slow movement ofthe damper in the same direction as instep (1); (3) threeforce unbalance of the balance, continual removal ofthe third force and intermittent damper of such magnitude as to be ineffect a slow positioning of the damper in the direction opposite tothat in step (1). The damper, therefore, upon an increase in ilow, isfirst rapidly closed and then intermittently opened during definiteperiods of time and closed during shorter periods of time, which ineifectcorrespond with a quick over-travel followed by a slow` return tothe' desired nal position. Regulation of the dam er in this manner aordsa rapid control o the flow while preventing huntin of the system as thedamper is automatica ly returned from its position of overtravel priorto the complete reaction on the balance of the damper over-travel.

If, instead of an initial increase of flow, the flow had decreased forany reason, the operation of the regulator would lia-ve been just thereverse of that above described.. A decrease in pressure within bell 10would cause the closure of contacts 23'and V25 with consequent operationof both motors, the compensating motor acting to first lower rod 11 andthen return it to normal position, and the regulating motor actingA toopen the damper too widely, followed bya partial closure thereof to afinal position corresponding to the desired opening to compensate forthe initial decrease of flow. A

In the operation of the regulator of my patent above referred to, thedam r is moved directly to its final -position without overtravel and`thetemporary force is removed from the balance at a rate relativelymuch slower than that at which it is applied.Y My

present re ulator, by causing initial overtravel of t 1e damper'followed by an automatic return to its iin'al position and by therelatively rapid removal of the temporary force, insures more rapidregulation than can be effected by the patented device, Withoutreduction in the sensitivity, accuracy or stability of the formerregulator.

'I have now illustrated one embodiment 'of my invention. For convenienceI have shown new regulator arranged to maintain constant the of a damconcerne pressure of a fluid by the control er. Obviously my inventionis not withl the particular element controlled nor with the controllingforce or forces which in the articular case illustrated was a constant,being the value introduced by the position of the weight 8 upon thelever. Obviously this weight can be replaced with any desired fixed orvarying force or'forces without aecting my invention. The particularmeans herein shown for acting on the lever with a force varying asa'unction of the element controlled is of course immaterial, as anydesired means may be used.

In the modification illustrated rod 11 and damper 1 are arranged to bedirectly driven by't e compensating and re ulating motors respectively;the circuits of t e motors being opened and closed by the apparatus.Obviously my invention. is not limited to such s cific arrangement, asany means for suita ly connecting driving means to rod 11 andy damper 1upon closure of the various electric circuits could be as readilemployed. In a co-pending application, erial No. 346,917, filed March14, 1929, patented Nov. 25', 1930, No. 1,782,832, have shown anddescribed an improved modification of the regulator of my Patent No.1,658,577. In the regulator of the above application a continuouslyoperating electric motor is arran ed to be coupled to a regulatedelementz suc as a dam r or valve to move the same in either directionupon ener ization of appropriate electromagnets. uch an ari-an ementcorresponding with the element C o Fig. 7 of said application could beemployed in connection with the present regulator to control either orboth rod 1l and damper 1. Obviously other substitutions or rearrangementof parts could be made without departing from the spirit of myinvention.

il claim: e

1.-]ln a regulator, member subjected to opposing regulating andregulated forcesy and causing regulating changes when such forces becomeunbalanced, and a modifying mechanism brought into operation by themovement of the primary re lating member comprising means for graduallyadding and withdrawing a third force to the primary regulating memberand means controlled jointly by the primary regulating member and themodifying mechanism for a primary regulating v varying the rapidity anddirection of the during izo ance is normally maintained in equilibriumY. during artificial when said regulating force is that desired, the

combination comprising means brought into` operation upon departure fromnormal equilibrium of the balance for artificially restoring equilibriumby the addition of a third force to the balance, a controlled elementadapted when moved to effect the force tobe regulated, and means broughtinto operation by the departure from normal equilibrium of the balanceand continuing iuoperation n uilibrium thereof adapted when operated toirectly adjust the position of said element to such position as willrestore the regulated force to the value desired. 4. The combinationaccording to claim 3 wherein the last mentioned means is arranged tocause said element to be adjusted to too great an extent durinaddition-of said third orce and during arti cial equilibrium and to beintermittently moved toward and away from such extreme position duringdecrease in said third force due to departure of the balance in theopposite direction whereby the element will reach the desired finalposition and lnor-mal equilibrium will be obtained when the third forcehas been completely;l removed.

5. a regulator for controlling the positionI of an element, a primaryregulating member normally in equilibrium under opposed regulating andregulated forces, means ught into operation upon a departure of saidmember from equilibrium for simultaneously positioning the element andfor adding a third force to said member in a direction to artificiallyrestore equilibrium thereof, means for maintainin constant said thirdforce and for positioning the element at a slower rate during artificialequilibrium of the member and means'brought into operation upondeparture from artificial unbalance due to excess of said third forcefor removing said force and for oppositely positioning said element.

6. A regulator for controlling the position of an element com rising abalance, a member adapted when 'splaced from normal position to ap ly aforce to said balance means controlled y the position of said balancefor moving said member, and means alternately controlled by the positionof said balance and by the displacement of said member for moving theelement. v

7. A regulator according to claim 6 wherein the said means for movingthe element is arranged to be controlled by the position of the balancefor relatively longer periods of time than by the displacement of saidmember. .Y

A8. In a re lator for controlling the position of an e ement, abalanceacted upon by a controlling force and by a force responsive tothe positlon of the element vand normally in neutral position, when said'forces are in equilibrium means controlled by the departure of thebalance from neutral for ad a third force to the balance in a directionto restore neutrality, means brought into operation during increaseinsaid third force for moving said element in such direction as torestore equilibrium bet-Ween the force responsive thereto and thecontrolling force, and means brought into operation during decrease insaid third force for moving sai element intermittently in oppositedirections.

9. A regulator according to claim 8 wherein said last mentioned means isarranged to move the element in a direction to restore equilibriumbetween the force varying responsively with the position of the elementand Vthe controlling force .for relatively shorter periods of time thanto move it in the ance, a regulating motor adapted to control theelement, and means for operatin said regulating motor in the samedirection. as said compensating motor during increase of said additionalforce and partly in the same direction and partly in the oppositedirection during decrease of said additional force.

11. In a regulator of the type wherein a regulating force' opposes aforce varying as a function of" the element controlled upon a balance toeli'ect control of the element upon departure of the balance fromneutral, the combination comprising a movable device adapted whendisplaced from normal position to apply an additional force to saidbalance, means thrown into operation upon a departure of said balancefrom neutra-l for moving said device in' such direction as to,

tendto restore the balance to neutral, driving means for controllingsaid element arranged to be operated either by said means thrown intooperation upon departure of the balance from neutral or by meansdeperdent upon the direction of displacement of said movable device fromnormal, and continuously operatin means adapted to alternately connectsaid riving means to said operating meansv'aherefor.

12. The combination according to claim 11 including a horizontallylmovable member biased toward one position and intermittently drivenagainst the bias by said continuously operating means, said horizontallymovable member being adapted when said member is in ozeition and whensaid'balance has depa rfrom neutral to closean electrical circuit forsaid driving'means, and adapted when said member is in another positionand said device is displaced from normal to close another electricalcircuit' for said driving means.

13. A regulator for controlling the posi-l tion of an element com risinga balance, amember adapted when isplaced from normal position to a ply aforce to said balance, means controlle by the position of said balancefor movin said member, means for adjusting the position of the element,a movable device adapted to control the operation of'said last mentionedmeans jointly with the 'tion of said balance in one position and ]ointlywith the position of said member in another position, and means orintermittently movin said device from one of said positions to t e otherof said positions.

14. A regulator according to claim 13 wherein said last mentioned meansincludes biasing means normally tending to hold said device in theposition where control of said driving means is eiected 'ointly with theposition of the balance and a continuously rotated cam adapted tointermittently move said device against the biasing means to suchposition as to control the driving means joint- 1y with the position ofdisplacement of said member.

15. A regulator for controlling. the 'position of an element comprisingin combination a reversible switch the movable member of which is actedupon by a controlling force and by a force responsive to the position otthe element, a device adapted when displaced from normal osition to adda force to the movable mem `r of said switch, electrical driving meansfor movin said device` and actuated u on a closure o said switch, a second devlce biased' toward one position and adapted to be intermittentlymoved for rel atively short periods of time to a second osition againstsaid bias, and electrical dmving means for positioning said elementactuated When said switch is closed and said second device is'in thefirst mentioned position and actuated when said first device is.displaced and said second device is in the last mentioned position.'

16. The combination according to claim 15 in which said electricaldriving means for positioning the element is operated in the samedirection at each position lof said second device during increase 1n theadditional force and in opposite directions at .each position duringdecrease in said additional force.

'i ony whereof, I have signed my name to this specification., l

- CHARLES H. SHOOT.

